The invention relates to a method for controlling several pumps as well as a correspondingly designed pump.
There are known pumps, in particular submersible pumps which are applied in pump sumps in order to pump away the fluid collected in the pump sump given a predefined fluid level. With such a pump sump one often uses several pumps. With the application of several pumps it is to be ensured that the pumps are uniformly operated in capacity so that the pumps also wear uniformly. The alternating activation of the individual pumps requires a central control which alternately switches the pumps on and off. The installation of such a central control renders the assembly and operation of the pumps more difficult.
From DE 199 27 365 C2 there is known a control of several pumps in a common pump sump, according to which even when achieving a predefined switching threshold is not switched on if it is not the turn of the respective pump in alternating operation of several pumps. This control requires additional signals or information on the number of applied pumps in order to be able to set an alternating operation. Furthermore when starting for the first time one requires an increased control and setting effort in order to set the alternating operation with a certain number of pumps. Furthermore the fact that a pump which is not next in line is not switched on even when achieving its switching threshold leads to problems when the respective pump which is next in line in alternating operation fails.